Publisher's blurb:
Across the planes of existence and the world of Toril, new allies gather to challenge the multiverse's toughest opponents.
To celebrate the release of Mordenkainen's Tome of Foes, which has unleashed hordes of dastardly enemies upon the tables of the world, Mordenkainen has enlisted the Clan Crafter Hralding to create this Codex of Allies, a collection of heroes and villains to call upon when the multiverse is in peril. The codex is filled with beautiful full color art and dotted with notes and insights from Mordenkainen himself.
There are 33 archetypes in within the codex, many of which are revised and re-balanced from Unearthed Arcana (UA) or from Mike Mearls Happy Fun Hour (HFH). The revised versions in this codex are intended to replace the originals until the archetypes are released in an official supplement.